Gyrotron FU series - current status of development and applications

The gyrotrons developed at Fukui University ("Gyrotron FU series") are high -frequency, medium-power devices, covering broad frequency bands in the mil limeter and submillimeter wavelength regions. Currently, the "Gyrotron FU s eries" consists of eight gyrotrons. Distinguishing features of these device s are described. Frequency tunability from 38 to 889 GHz; frequency and amp litude modulation of generated radiation; complete cw operation for long pe riods, exceeding 15 h and high level of stabilization of the Output power b y feed-back control of the anode potential. The gyrotrons from FU series we re successfully used in plasma scattering experiments, electron spin resona nce spectroscopy and in-depth studies of mode competition and mode cooperat ion. In this paper, we summarize and illustrate the achievements of the "Gy rotron FU series" and present some of the ongoing projects for development of novel gyro-devices and quasi-optical transmission systems. (C) 2001 Else vier Science Ltd. All rights reserved.